Response to Letter Regarding Article, “DITPA (3,5-Diiodothyropropionic Acid), a Thyroid Hormone Analog to Treat Heart Failure: Phase II Trial Veterans Affairs Cooperative Study”
We are glad that Dr Pingitore and his colleagues share our interest in use of thyromimetic agents to enhance cardiac performance. Inasmuch as a negative finding with respect to heart failure benefit with a low dose would have been an inconclusive study, we elected to administer the presumed maximum tolerated dose. In retrospect, we agree that the DITPA dose we used was too high, but available resources allowed only a single dose to be tested. As noted, we did see some beneficial effects and have tentatively identified a dose (90 mg/d) that might provide a better balance between benefit and tolerability, for future study.
Drs Goldman, Morkin, Gregory Pennock, and Joseph Bahl received a use patent for 3,5-diiodothyropropionic acid (DITPA) that was assigned to the University of Arizona: US Patent No. 6,534,676 B2 UA #03 to 075. The Department of Veterans Affairs and the University of Arizona have an agreement regarding the management of co-owned inventions and/or intellectual property that enables the university to direct matters related to patenting, marketing, and licensing of co-owned inventions. The University of Arizona licensed DITPA to Titan Pharmaceutical, South San Francisco, Calif. Dr Goldman previously owned stock in Titan; Drs Goldman, Morkin, and Ladenson were consultants for Titan, but no longer receive payments. Dr Ladenson has received grant support from Titan. In December 2008, Titan Pharmaceutical discontinued the development of DITPA, and the license has reverted to the University of Arizona. The first US patent application for DITPA was issued as US 6,534,676 on March 18, 2003; the Canadian counterpart is CA 2002243801, which was issued on March 22, 2007. A second US patent application for analogs of DITPA was issued as US 6,716,877 on April 6, 2004.
Drs Goldman and McCarren each are considered first authors based on equal contributions.